1. Field
This disclosure relates generally to motion detection on an image.
2. Background
Many techniques are known to detect motion within a frame or an image when the frame is part of a series of frames, as in a movie or video clip. First, a single frame is selected from the series of consecutive, related frames from a continuous reel (e.g., a movie, or video clip), where each frame represents an image from one of a consecutive sequence of time intervals. Second, the selected frame is compared to a frame that precedes it and/or a frame that follows it in the series. Finally, based on the comparisons of the selected frame to the preceding and/or subsequent frames, it is determined which portion or portions of the selected frame have changed. The changed portions are regarded as moving objects.
However, difficulties arise in situations when the selected frame or image stands alone, is not part of a series of frames, is part of a series of time-lapsed images, or otherwise is selected from a series of frames but is not compared against any of the frames of the series that immediately precedes and/or are subsequent to the selected frame. In such cases, the above technique cannot be applied when trying to determine which portions of a selected image or frame are moving, were moving or are likely to move at the time of image capture, because there are no preceding or subsequent frames that may be referenced to make such a determination.
Comparing a selected frame to other frames from the series, as described above, and other conventional techniques for moving object detection include differentiating foreground objects from background objects based on a user's input. For example, in a given frame, a user would select objects in the frame to indicate which objects of the frame are the foreground objects and which objects of the frame are background objects. Then based on the selected foreground objects, as determined by the user's input, conventional motion detection techniques are then applied to analyze foreground objects for motion as discussed above.